He said initial reports indicated that dozens of labourers remained trapped after the blast in the coastal town of Gadani. He added that several workers jumped overboard into the sea as the fire raged.

Mr Abdullah said rescuers were taking the casualties to a hospital in Karachi, the capital of southern Sindh province.

Gadani is one of the world's largest ship-breaking yards and was established in the 1970s. Labourers are often injured while breaking ships there, mainly due to poor safety measures.

AP

Shortly after the accident, Prime Minister Nawaz Sharif issued a statement expressing sorrow for the "loss of valuable lives".

He ordered authorities to expedite the operation to rescue those stranded on board the burning ship, and urged health officials to provide the best possible care to those wounded.